Can anyone help to create a SQL code which could list movies which have been searched under 2 or more tags for the tables below? E.g. I want to list all movies which have the tags “4star” AND “Drama”.
Tables
I have managed to create one which lists movies which have either one or another tag… thus.
Select tblMovies.MovieName
FROM tblMovies, tblBridge, tblTags
WHERE ((tblTags.TagID=1) OR (tblTags.TagID=5))
And tblTags.TagID = tblBridge.TagID
And tblBridge.MediaID= tblMovies.MovieID
Which gives Star Wars, Aliens, Goodfellows, Mermaids.
But I'm struggling with the AND code which would give Goodfellows and The Godfather if I search for movies which have tags 1 (4star) and 7 (Drama) for example.
Many thanks.
You are looking for movies for which exist both tags 1 and 7. We don't use joins usually when we only want to check whether data exists. We use EXISTS. Or IN, which expresses the same thing (movies that are in the set of tag 1 movies and also in the set of tag 7 movies).
The idea is that we select FROM the table we want to see results from. And we use the WHERE clause to tell the DBMS which rows we want to see.
With EXISTS
SELECT m.moviename
FROM tblmovies m
WHERE EXISTS (SELECT null FROM tblbridge b WHERE b.tagid = 1 AND b.movieid = m.movieid)
AND EXISTS (SELECT null FROM tblbridge b WHERE b.tagid = 7 AND b.movieid = m.movieid)
ORDER BY m.moviename;
With IN
SELECT m.moviename
FROM tblmovies m
WHERE m.movieid IN (SELECT b.movieid FROM tblbridge b WHERE b.tagid = 1)
AND m.movieid IN (SELECT b.movieid FROM tblbridge b WHERE b.tagid = 7)
ORDER BY m.moviename;
I should add that these are not the only options available to get that result. But they are the straight-forward ones. (Another is conditional aggregation, but you'll learn this later.)
Related
I have one main table and join other tables via left outer or right outer outer join.One row of main table have over 30 row in join query as result. And I try pagination. But the problem is I can not know how many rows will it return for one main table row result.
Example :
Main table first row result is in my query 40 rows.
Main table second row result is 120 row.
Problem(Question) UPDATE:
For pagination I need give the pagesize the count of select result. But I can not know the right count for my select result. Example I give page no 1 and pagesize 50, because of this I cant get the right result.I need give the right pagesize for my main table top 10 result. Maybe for top 10 row will the result row count 200 but my page size is 50 this is the problem.
I am using Sql 2014. I need it for my ASP.NET project but is not important.
Sample UPDATE :
it is like searching an hotel for booking. Your main table is hotel table. And the another things are (mediatable)images, (mediatable)videos, (placetable)location and maybe (commenttable)comments they are more than one rows and have one to many relationship for the hotel. For one hotel the result will like 100, 50 or 10 rows for this all info. And I am trying to paginate this hotels result. I need get always 20 or 30 or 50 hotels for performance in my project.
Sample Query UPDATE :
SELECT
*
FROM
KisiselCoach KC
JOIN WorkPlace WP
ON KC.KisiselCoachId = WP.WorkPlaceOwnerId
JOIN Album A
ON KC.KisiselCoachId = A.AlbumId
JOIN Media M
ON A.AlbumId = M.AlbumId
LEFT JOIN Rating R
ON KC.KisiselCoachId = R.OylananId
JOIN FrUser Fr
ON KC.CoachId = Fr.UserId
JOIN UserJob UJ
ON KC.KisiselCoachId = UJ.UserJobOwnerId
JOIN Job J
ON UJ.JobId = J.JobId
JOIN UserExpertise UserEx
ON KC.KisiselCoachId = UserEx.UserExpertiseOwnerId
JOIN Expertise Ex
ON UserEx.ExpertiseId = Ex.ExpertiseId
Hotel Table :
HotelId HotelName
1 Barcelona
2 Berlin
Media Table :
MediaID MediaUrl HotelId
1 www.xxx.com 1
2 www.xxx.com 1
3 www.xxx.com 1
4 www.xxx.com 1
Location Table :
LocationId Adress HotelId
1 xyz, Berlin 1
2 xyz, Nice 1
3 xyz, Sevilla 1
4 xyz, Barcelona 1
Comment Table :
CommentId Comment HotelId
1 you are cool 1
2 you are great 1
3 you are bad 1
4 hmm you are okey 1
This is only sample! I have 9999999 hotels in my database. Imagine a hotel maybe it has 100 images maybe zero. I can not know this. And I need get 20 hotels in my result(pagination). But 20 hotels means 1000 rows maybe or 100 rows.
First, your query is poorly written for readability flow / relationship of tables. I have updated and indented to try and show how/where tables related in hierarchical relativity.
You also want to paginate, lets get back to that. Are you intending to show every record as a possible item, or did you intend to show a "parent" level set of data... Ex so you have only one instance per Media, Per User, or whatever, then once that entry is selected you would show details for that one entity? if so, I would do a query of DISTINCT at the top-level, or at least grab the few columns with a count(*) of child records it has to show at the next level.
Also, mixing inner, left and right joins can be confusing. Typically a right-join means you want the records from the right-table of the join. Could this be rewritten to have all required tables to the left, and non-required being left-join TO the secondary table?
Clarification of all these relationships would definitely help along with the context you are trying to get out of the pagination. I'll check for comments, but if lengthy, I would edit your original post question with additional details vs a long comment.
Here is my SOMEWHAT clarified query rewritten to what I THINK the relationships are within your database. Notice my indentations showing where table A -> B -> C -> D for readability. All of these are (INNER) JOINs indicating they all must have a match between all respective tables. If some things are NOT always there, they would be changed to LEFT JOINs
SELECT
*
FROM
KisiselCoach KC
JOIN WorkPlace WP
ON KC.KisiselCoachId = WP.WorkPlaceOwnerId
JOIN Album A
ON KC.KisiselCoachId = A.AlbumId
JOIN Media M
ON A.AlbumId = M.AlbumId
LEFT JOIN Rating R
ON KC.KisiselCoachId = R.OylananId
JOIN FrUser Fr
ON KC.CoachId = Fr.UserId
JOIN UserJob UJ
ON KC.KisiselCoachId = UJ.UserJobOwnerId
JOIN Job J
ON UJ.JobId = J.JobId
JOIN UserExpertise UserEx
ON KC.KisiselCoachId = UserEx.UserExpertiseOwnerId
JOIN Expertise Ex
ON UserEx.ExpertiseId = Ex.ExpertiseId
Readability of a query is a BIG help for yourself, and/or anyone assisting or following you. By not having the "on" clauses near the corresponding joins can be very confusing to follow.
Also, which is your PRIMARY table where the rest are lookup reference tables.
ADDITION PER COMMENT
Ok, so I updated a query which appears to have no context to the sample data and what you want in your post. That said, I would start with a list of hotels only and a count(*) of things per hotel so you can give SOME indication of how much stuff you have in detail. Something like
select
H.HotelID,
H.HotelName,
coalesce( MedSum.recs, 0 ) as MediaItems,
coalesce( LocSum.recs, 0 ) as NumberOfLocations,
coalesce( ComSum.recs, 0 ) as NumberOfLocations
from
Hotel H
LEFT JOIN
( select M.HotelID,
count(*) recs
from Media M
group by M.HotelID ) MedSum
on H.HotelID = MedSum.HotelID
LEFT JOIN
( select L.HotelID,
count(*) recs
from Location L
group by L.HotelID ) LocSum
on H.HotelID = LocSum.HotelID
LEFT JOIN
( select C.HotelID,
count(*) recs
from Comment C
group by C.HotelID ) ComSum
on H.HotelID = ComSum.HotelID
order by
H.HotelName
--- apply any limit per pagination
Now this will return every hotel at a top-level and the total count of things per the hotel per the individual counts which may or not exist hence each sub-check is a LEFT-JOIN. Expose a page of 20 different hotels. Now, as soon as one person picks a single hotel, you can then drill-into the locations, media and comments per that one hotel.
Now, although this COULD work, having to do these counts on an every-time query might get very time consuming. You might want to add counter columns to your main hotel table representing such counts as being performed here. Then, via some nightly process, you could re-update the counts ONCE to get them primed across all history, then update counts only for those hotels that have new activity since entered the date prior. Not like you are going to have 1,000,000 posts of new images, new locations, new comments in a day, but of 22,000, then those are the only hotel records you would re-update counts for. Each incremental cycle would be short based on only the newest entries added. For the web, having some pre-aggregate counts, sums, etc is a big time saver where practical.
enter image description here
I have two tables :
UserInfo
Skill
and the join table between them called UserSkill as you can see at the
right part of the diagram.
I want to know whoever knows or is skillful in Java, what else he is skillful at. I mean for example I know java, Go, PHP, python and user number 2 knows java and python and CSS. So the answer to the question: whoever knows java what else he knows would be GO, PHP, Python and CSS.
It's like recommendation systems for example whoever but this product what else do they bought? Like what we have in amazon ..
What would be the best query for this ?
Thank you
More information:
UserInfo
U-id U-name
1 A
2 B
3 C
SkillInfo
S-id S-Name
1 Java
2 GO
3 PHP
4 Python
5 CSS
UserSkill:
U-id S-id
1 1
1 2
1 3
1 4
2 1
2 4
2 5
In SQL Server 2017 and Azure SQL DB you can use the new graph database capabilities and the new MATCH clause to answer queries like this, eg
SELECT FORMATMESSAGE ( 'User %s has skill %s and other skill %s.', [user1].[U-name], mainSkill.[S-name], otherSkill.[S-name] ) result
FROM
dbo.users user1,
dbo.hasSkill hasSkill1, dbo.skills mainSkill, dbo.hasSkill hasSkill2, dbo.skills otherSkill
WHERE mainSkill.[S-name] = 'CSS'
AND otherSkill.[S-name] != mainSkill.[S-name]
AND MATCH ( mainSkill<-(hasSkill1)-user1-(hasSkill2)->otherSkill);
My results:
Obviously you can answer the same queries with a relational approach, it's just a different way of doing things. Full script available here.
To make this more dynamic, replace the hard coded 'java' with a variable that you can pass to filter by any skill type, possibly make a stored procedure so you can pass the variable,
Edited column names as I didn't look at the image you provided:
--Outer query selects all skills of users which are not java and user has skill of java,
--the inner query selects all user ids where the user has a skill of java
SELECT sk.[SkillName], ui.[UserName], ui.[UserId]
FROM [dbo].[Skill] AS sk
INNER JOIN [dbo].[UserSkill] AS us
ON us.[SkillId] = sk.[SkillId]
INNER JOIN [dbo].[UserInfo] AS ui
ON ui.[UserId] = us.[UserId]
WHERE sk.[Skill] <> 'java' AND ui.[UserId] IN (
SELECT [UserId]
FROM [dbo].[UserInfo] ui
INNER JOIN [dbo].[UserSkill] us
ON us.[UserId] = ui.[UserId]
INNER JOIN [dbo].[Skill] sk
ON sk.[SkillId] = us.[SkillId]
WHERE sk.[SkillName] = 'java')
This is what I have found
--Formatted query
select
o.UserName, k.SkillName
from
UserSkill S
inner join
UserSkill SS on s.UserID = ss.UserID
and s.SkillID = 1
and ss.SkillID <> 1
inner join
Skill k on k.SkillID = ss.SkillID
inner join
UsersINFO O on o.UserID = ss.UserID
I am trying to make a summary table of all the items I have. I have a raw data table with 10 users who respectively have different items. There are maximum 3 different items and I want to do a count to see how many items each individual has. The following is my code.
Select b.Country,b.UserID,Num_including_fruits, Apple,Orange
from
(((SELECT o.Country,o.UserID, IIF(ISNULL(Count(o.UserID)),0,Count(o.UserID))
AS Num_including_fruits
FROM [SEA2_View] as o
GROUP BY o.UserID, o.Country
ORDER BY Country)as b
LEFT JOIN
(SELECT o.Country,o.UserID,IIF(ISNULL(Count(o.UserID)),0,Count(o.UserID)
AS Apple
FROM [APAC2_View] as o
WHERE o.fruit_status <>"fresh" AND o.HWType = "Apple"
GROUP BY o.Country,o.UserID)as d
ON (b.UserID = d.UserID))
LEFT JOIN
(SELECT o.Country,o.UserID,IIF(ISNULL(Count(o.UserID)),0,Count(o.UserID))
AS Orange
FROM [SEA2_View] as o
WHERE o.fruit_status <>"fresh" AND o.HWType = "Orange"
GROUP BY o.Country,o.UserID)as e
ON (d.UserID = e.UserID))
;
The first join returns the correct result but the second join somehow returns all 0, which is incorrect. Therefore please help! and I would appreciate any advice for best practice when it comes to joins in SQL. Thanks lot!
Are you sure you don't have a table naming error?
You're first joining [SEA2_View] with [APAC2_View]. The second join is joining with [SEA2_View] with itself.
I have one SQL statement as:
SELECT ARTICLES.NEWS_ARTCL_ID, ARTICLES.NEWS_ARTCL_TTL_DES,
ARTICLES.NEWS_ARTCL_CNTNT_T, ARTICLES.NEWS_ARTCL_PUB_DT,
ARTICLES.NEWS_ARTCL_AUTH_NM, ARTICLES.NEWS_ARTCL_URL, ARTICLES.MEDIA_URL,
ARTICLES.ARTCL_SRC_ID, SOURCES.ARTCL_SRC_NM, MEDIA.MEDIA_TYPE_DESCRIP
FROM
RSKLMOBILEB2E.NEWS_ARTICLE ARTICLES,
RSKLMOBILEB2E.MEDIA_TYPE MEDIA,
RSKLMOBILEB2E.ARTICLE_SOURCE SOURCES
WHERE ARTICLES.MEDIA_TYPE_IDENTIF = MEDIA.MEDIA_TYPE_IDENTIF
AND ARTICLES.ARTCL_SRC_ID = SOURCES.ARTCL_SRC_ID
AND ARTICLES.ARTCL_SRC_ID = 1
ORDER BY ARTICLES.NEWS_ARTCL_PUB_DT
Now I need to combine another SQL statement into one which is:
SELECT COUNT ( * )
FROM RSKLMOBILEB2E.NEWS_LIKES LIKES, RSKLMOBILEB2E.NEWS_ARTICLE ARTICLES
WHERE LIKES.NEWS_ARTCL_ID = ARTICLES.NEWS_ARTCL_ID
Basically I have one table which contains articles and I need to include the user likes which is in another table.
Use a subquery to add the likescount in your first query like this:
SELECT ARTICLES.NEWS_ARTCL_ID
,ARTICLES.NEWS_ARTCL_TTL_DES
,ARTICLES.NEWS_ARTCL_CNTNT_T
,ARTICLES.NEWS_ARTCL_PUB_DT
,ARTICLES.NEWS_ARTCL_AUTH_NM
,ARTICLES.NEWS_ARTCL_URL
,ARTICLES.MEDIA_URL
,ARTICLES.ARTCL_SRC_ID
,SOURCES.ARTCL_SRC_NM
,MEDIA.MEDIA_TYPE_DESCRIP
,(
SELECT COUNT(*)
FROM RSKLMOBILEB2E.NEWS_LIKES LIKES
WHERE LIKES.NEWS_ARTCL_ID = ARTICLES.NEWS_ARTCL_ID
) AS LikesCount
FROM RSKLMOBILEB2E.NEWS_ARTICLE ARTICLES
,RSKLMOBILEB2E.MEDIA_TYPE MEDIA
,RSKLMOBILEB2E.ARTICLE_SOURCE SOURCES
WHERE ARTICLES.MEDIA_TYPE_IDENTIF = MEDIA.MEDIA_TYPE_IDENTIF
AND ARTICLES.ARTCL_SRC_ID = SOURCES.ARTCL_SRC_ID
AND ARTICLES.ARTCL_SRC_ID = 1
ORDER BY ARTICLES.NEWS_ARTCL_PUB_DT;
I'm not sure what you are trying to achieve but it seems you want to count all the data from 2 tables. You can edit your query to something like this.
SELECT COUNT (ARTICLES.*) FROM RSKLMOBILEB2E.NEWS_LIKES LIKES
JOIN RSKLMOBILEB2E.NEWS_ARTICLE ARTICLES
ON LIKES.NEWS_ARTCL_ID = ARTICLES.NEWS_ARTCL_ID
I think that solution is in using Analytic Functions. Please have a look on https://oracle-base.com/articles/misc/analytic-functions
Please check following query (keep in mind I have no idea about your table structures). Due to left join records might be duplicated, this is why grouping is added.
SELECT ARTICLES.NEWS_ARTCL_ID, ARTICLES.NEWS_ARTCL_TTL_DES,
ARTICLES.NEWS_ARTCL_CNTNT_T, ARTICLES.NEWS_ARTCL_PUB_DT,
ARTICLES.NEWS_ARTCL_AUTH_NM, ARTICLES.NEWS_ARTCL_URL, ARTICLES.MEDIA_URL,
ARTICLES.ARTCL_SRC_ID, SOURCES.ARTCL_SRC_NM, MEDIA.MEDIA_TYPE_DESCRIP,
count(LIKES.ID) over ( partition by ARTICLES.NEWS_ARTCL_ID ) as num_likes
FROM RSKLMOBILEB2E.NEWS_ARTICLE ARTICLES
join RSKLMOBILEB2E.MEDIA_TYPE MEDIA
on ARTICLES.MEDIA_TYPE_IDENTIF = MEDIA.MEDIA_TYPE_IDENTIF
join RSKLMOBILEB2E.ARTICLE_SOURCE SOURCES
on ARTICLES.ARTCL_SRC_ID = SOURCES.ARTCL_SRC_ID
LEFT JOIN RSKLMOBILEB2E.NEWS_LIKES LIKES
ON LIKES.NEWS_ARTCL_ID = ARTICLES.NEWS_ARTCL_ID
WHERE
ARTICLES.ARTCL_SRC_ID = 1
group by ARTICLES.NEWS_ARTCL_ID, ARTICLES.NEWS_ARTCL_TTL_DES,
ARTICLES.NEWS_ARTCL_CNTNT_T, ARTICLES.NEWS_ARTCL_PUB_DT,
ARTICLES.NEWS_ARTCL_AUTH_NM, ARTICLES.NEWS_ARTCL_URL, ARTICLES.MEDIA_URL,
ARTICLES.ARTCL_SRC_ID, SOURCES.ARTCL_SRC_NM, MEDIA.MEDIA_TYPE_DESCRIP
ORDER BY ARTICLES.NEWS_ARTCL_PUB_DT
I also changed coma-separated list of tables from where condition to joins. I think this is more readable since table join conditions are separated from result filtering in where clause.
I know there are a lot of other SO entries that seem like this one, but I haven't found one that actually answers my question so hopefully one of you can either answer it or point me to another SO question that is related.
Basically, I have the following query that returns Venues that have any CheckIns that contain the searched Keyword ("foobar" in this example).
SELECT DISTINCT v.*
FROM "venues" v
INNER JOIN "check_ins" c ON c."venue_id" = v."id"
INNER JOIN "keywordings" ks ON ks."check_in_id" = c."id"
INNER JOIN "keywords" k ON ks."keyword_id" = k."id"
WHERE (k."name" = 'foobar')
I want to SELECT and ORDER BY the count of the matched Keyword for each given Venue. E.g. if there have been 5 CheckIns that have been created, associated with that Keyword, then there should be a returned column (called something like keyword_count) with the value 5 which is sorted.
Ideally this should be done without any queries in the SELECT clause, or preferably none at all.
I've been struggling with this for a while and my mind is just going blank (perhaps it's been too long a day) so some help would be greatly appreciated here.
Thanks in advance!
Sounds like you need something like:
SELECT v.x, v.y, count(*) AS keyword_count
FROM "venues" v
INNER JOIN "check_ins" c ON c."venue_id" = v."id"
INNER JOIN "keywordings" ks ON ks."check_in_id" = c."id"
INNER JOIN "keywords" k ON ks."keyword_id" = k."id"
WHERE (k."name" = 'foobar')
GROUP BY v.x, v.y
ORDER BY 3